1 / 9

Targeting Grade C

GCSE Mathematics. Targeting Grade C. Number Unit 4 Percentages and Interest. If not you need. Can you: Find percentages of amounts Find percentage increase or decrease Try a test Find simple interest Find compound interest Try a test.

rayc
Download Presentation

Targeting Grade C

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GCSE Mathematics Targeting Grade C Number Unit 4 Percentages and Interest

  2. If not you need • Can you: • Find percentages of amounts • Find percentage increase or decrease • Try a test • Find simple interest • Find compound interest • Try a test TOP: Review how to find simple percentages Practice 1: Splitting percentages up Practice 2: Finding percentage increase and decrease TAIL 1 Practice 3: Finding simple interest Practice 4: Finding compound interest TAIL 2

  3. Remember to split the amount into 10% (by dividing by 10) and then multiply by the number of 10s you need! TOP:Solve these simple percentage questions. • Find 10% of £20 • Find 50% of £100 • Find 30% of £60 • Find 70% of £120 • Find 75% of £200 Lesson

  4. Split your percentage into parts like 10%, 5%, 2 ½% and 1% Practice 1:Solve these percentage problems. • Find 35% of £120 • Find 83% of £250 • Find 12% of 75kg • Find 17 ½% of 70 miles • Find 24% of £65.50 Remember to find 10%, then 1% (by dividing your 10% by 10), or 5% (by dividing your 10% by 2), or ½% (by dividing your 1% by 2), or 2 ½% (by dividing 5% by 2. Lesson

  5. One way to increase or decrease amounts by percentages is to find the percentage and then add (to increase) or subtract (to decrease) Practice 2:Find these percentage increases. • Increase £100 by 15% • Increase 85kg by 12 ½% • Increase 754 m by 68% Find these percentage decreases. • Decrease £100 by 75% • Decrease 65 miles by 34% • Decrease 378 km by 7 ½% Lesson

  6. TAIL 1 Are you ready for the answers ? • The selling price of a computer is the list price plus VAT at 17 ½ %. The list price of a computer is £786. • Work out the selling price of the computer. (1) 17 ½ /100  786 = 137.55 137.55 + 786 = £923.55 (2) 60/100  5300 = £3180 (2) Work out 60% of 5300 kg. (3) Frances sees three different advertisements for jeans. Bob’s – 15% off £30 Disco’s – ⅔ of £36 Sanjay’s – £22 + 17 ½% VAT Work out the cost of the jeans in each advertisement. (a) Bob's (b) Disco's (c) Sanjay's (3) (a) 15/100  30 = £4.50 30 – 4.50 = 25.50 (b) 2/3  36 = £24 (c) 17.5/100  22 + 22 = £25.80 Lesson

  7. Find the interest for one year then multiply by the number of years! Practice 3: Find the simple interest for the following: • £60 for 2 years at 4% interest per annum • £150 for 3 years at 7.5% interest per annum • £5000 for 6 years at 3% p.a. • £2500 for 10 years at 12.5% p.a. • £750 for 5 years at 6.5% p.a. Lesson

  8. Remember the formula (1+(percentage  100))number of yearsto help you e.g. for (1) do £150  (1.07)2 Practice 4: Find the compound interest for the following: • £150 for 2 years at 7% p.a. • £500 for 3 years at 12% p.a. • £7500 for 3 years at 3.5% p.a. • £65 for 2 years at 5% p.a. • £2500 for 4 years at 6.5% p.a. Lesson

  9. TAIL 2 (1) 5/100  269.30 = 13.465 269.30 – 13.465 = 255.835 = £255.84 (1) Yesterday Simon repaired a computer and charged a total of £269.30. Simon reduces his charges by 5% when he is paid promptly. He was paid promptly for yesterday's work on the computer. Work out how much he was paid. (2) Jane is going to buy a computer for £480 + 17 ½ % VAT. Work out the total price, including VAT, that Jane will pay for the computer. (3) Find the simple interest on £2500 invested for 2 years at 6% per year. (4) £5000 is invested for 3 years at 4% per annum compound interest. Work out the total interest earned over the three years. • Work out the simple interest on £530 at 4.5% per annum after 3 years. (2) 17 ½ /100  480 + 480 = 84 + 480 = £564 (3) 6/100  2500 = 150 “150”  2 = £300 (4) 1.043 5000 = £5624.32 (5) 4.5/100  530 = 23.85 “23.85”  3 = £71.55 Are you ready for the answers ? Lesson

More Related